Aluminum salts of 3-acetyl-18{62 -glycyrrhetinic acid

ABSTRACT

Aluminum salts of 3-acetyl-18 Beta -glycyrrhetinic acid are prepared by reacting the acid with alcoholates of aluminum and are useful primarily in treating disorders of the alimentary canal such as, for example, gastric ulcers.

United- States Patent 1 Bonati Oct. 9, 1973 [54] ALUMINUM SALTS OF OTHER PUBLICATIONS 3-ACETYL-ISfi-GLYCYRRHETINIC ACID 75 Inventor; an 80mm, Milan Italy Chemical Abstracts, Vol. 73, 64754p (1970).

[73] Assignee: Dott. Inverni & Della Beffa S.p.A.,

Milan, Italy Primary Examiner-l-lelen M. S. Sneed Filed Oct 27 1970 Att0rney-Browdy & Neimark [2]] App]. No.: 84,911

I [5 7] ABSTRACT 52 11.8. CI. 260 448 R 260 514.5, 424 296, 1 I 1/ Aluminum salts of 3-acetyl-l 8B-glycyrrhetinic acid are [51} Int. Cl. C07f 5/06 Prepared by reacting the acid with alcoholates of [58] Field of Search 260/448 R minum and are useful Primarily in "eating dismders of the alimentary canal such as, for example, gastric ul- [56] References Cited FOREIGN PATENTS OR APPLICATIONS 2/1964 Great Britain 4 Claims, No Drawings "iii acc'b'riiii wiih iii invention it has bii fdiiii that salts of 3-acetyl-18B-glycyrrhetinic acid with aluminum possess optimum healing and anti-inflammatory properties which are very useful in the treatment of disorders of the alimentary canal such as gastric and duodenal ulcers, gastritis and gastroduodenitis, particularly such disorders caused by medicaments. These substances may moreover be employed in the therapy of pharyngitic, pharyngotracheitis, corneal ulcers, colitis (especially ulcerative colitis dermatitis, dormatosis, decubitus ulcers, dormant ulcers, varicose ulcers, rhagades, haemorrhoids and erosions of the epithelium of the female genital passages.

The salts of 3-acetyl-b18B-glycyrrehetinic acid which are referred to are novel and possess not only the healing, anti-ulcer and anti-i nflammatory properties of the free acid, but also the pharmacological properites of aluminum, in particular the antiacid action.

Thus in accordance with one aspect of the present invention there are provided aluminum salts of 3-acetyl-18B-glycyrrhetinic acid of the formula wherein Glyc. represents a I 3-acetyl-18B-glycyrrhetinate group; OR represents a group selected from the group consisting of hydroxy and alkoxy; and x is O or a positive integer less than 3.

The invention also includes pharmaceutical preparations containing an aluminum salt of 3-acety l-l8B- glycyrrhetinic acid. These preparations comprise a diluent or carrier for the active ingredients and may in addition contain other drugs. Useful excipients include starch, talc, sodium alginate and magnesium stearate. The preparations may be administered in the form of tablets or suppositories, or as powders or ointments.

The pharmaceutical preparations may also include anti-acids such as aluminum hydroxide, glycine and aluminum silicate.

The new salts of 3-acetyll 8B-glycyrrhetinic acid can be prepared by reaction between 3-acetyl-l8figlycyrrhetinic acid and an aluminum alcoholate. Preferably lower alcoholates are used, i.e. alcoholates in which the alkoxy group or groups have from one to four carbon atoms. The salification reaction may be carried out at room temperature or at an elevated temperature in conventional fashion, preferably in the presence of organic solvents. As organic solvents may be used alcohols, ethers, ketones, chlorinated solvents (methylene chloride, chloroform) ethyl acetate etc.

Since the metal has a valency greater than one, it is possible to obtain a neutral salt or a basic salt, according to the ratio of the reactants.

The basic salts obtained may be represented by the formula A where R is hydrogen or an alkyl group corresponding to the alkoxy group of the alcoholate used in the preparation of the salt and Glyc. represents a 3-acetyl-l8/3-glycyrrhetinate group and x is l or 2. The basic salts containing alkoxy groups may be obtained by carrying out the salification reaction in the absence of water. If required these basic salts may be converted to basic salts containing hydroxyl groups (i.e., R H in the above formula) by contacting the salts with the stoichiometric requirement of water. Alternatively the basic salts containing hydroxyl groups may be produced by carrying out th e 'salification reaction in the presence of water.

Thus, it has been possible to obtain aluminum mono-, diand tri-3-acetyl-l8/3-glycyrrhetinate, in the case of the monoand disalts the remaining valencies of the aluminum may be satisfied by hydroxyl and/or alkoxy groups.

In many cases, the solubility of these new salts in organic solvents is very high, while the solubility in water is generally very low.

As a general rule, the solubility of the salts of 3-ac etyl-l 8B-glycyrrhetinic acid, i.e. increases from the basic salts to the neutral salts: aluminum tri-3-acety1- l8B-glycyrrhetinate is much more soluble in chloroform than aluminum mono-3-acetyl-l8B- glycyrrhetinate.

Pharmacological data.

In these experiments, reference is made to the following publications by number: l. Litchfield J.T. and Wilcoxon F .J Pharmacol. exp.

Ther.96, 99,1949 2. Shay H., Kamarov S.A., Fels S.S., Meranze D., Gruenstein M. and Spilet M.; Gastroenterology 5, 43, 1945. 3. Keyrilainen T.O. and Passonen M.K.; Acta Pharmacol. et toxicol, 13, 22, 1957 4. Winter C.A., Risley EA. and Nuss G.W.; Proc.

Exp. Biol. Med. 3, 544, 1962 5. Van Arman C.G., Begany A.J. Miller L.M. and Pless H.H.; J. Pharm. Exp. Ther., 150, 328, 1965 6. Cahen R., Pessonier A.; C.R.Soc. Biol. 157, 477,

1963 7. Bonfils S., Lefooghe S., Rossi C, and Lambling A.:

CR. Soc. Biol. 151 1149, 1957. Toxicity This was studied in male rats of the Sprague-Dawley strain weighing 220 290 g by oral and intraperitoneal administration, observation being extended for a duration of 10 days.

The LD 50 was evaluated by the Litchfield and Wilcoxon method (I).

Tables land 2 show the values of the LD 50 obtained in rats by the oral and intraperitoneal methods, respec- TAB LE 2 Continued Aluminum tri-3- acety1-18B- glycyrrhetinate 40 3300 Anti-ulcer activity This was studied by comparison of experimental ulcers produced by ligature of the pylorus, according to Shay (2).

Ligature of the pylorus was carried out under light anaesthesia with ether on rates which had been kept fasting for 48 hours in single cages with water ad libitum. The rats were replaced in the cages without food and without water, and were killed 17 hours later. The stomach was opened along the lower bend and examined to determine the formation of ulcers therein in accordance with the following standard of classification proposed by Keyrilainen and Passonen (3).

Class I small ulcers 0.2 mm value 1 Class 11 medium ulcers 2-5 mm value 5 Class 111 large ulcers 5-10 mm value Class IV very large ulcers 10 mm value Perforation value 20 There were than calculated: the ulcer index =sum of the values of all the classes/number of animals, the percentage variations of the ulcer index of therats treated with respect to the controls, and the number of stomachs protected from the formation of ulcers, those as such.

The administration of the substances was effected by gastric probe and was repeated three times, 48 and 24 hours prior to the ligature of the pylorusand immediately after the operation.

Each of the substances examined, suspended in gum arabic, was administered to groups of 10 13 rats. The data obtained are summarised in Table 3.

the mucous membranewas then examined. having not more than two small ulcers being regarded Activity on the repair of gastric ulcers The Cahen and Passonier technique (6) was used.

The substances were administered orally, with the 10 doses fixed and divided in two in the course of the day;

half in the morning and half in the evening.

Rats to which the vehicle of the substances under examination, constituted by gum arabic in a concentra- 15 tion of 10% in water was administered, were kept as control.

The treatments were continued for 1 8 days.

in groups of 8 at a time, the animals were killed by decapitation 24 hours, 3, 6 and 9 days after the cessation of the immobilization, 12 hours after the last administration of the drugs.

The stomachs were removed from the animals killed immediately after the period of immobilization (check on the ulcerogenic effectiveness of this period) or at the above-indicated times after the cessation of the restraint, were washed with physiological solution and Account was taken of the number of unhealed ulcers (U) and of the number of ulcers healed or in a stage of repair (UH).

I An ulcer index based on the ratio between the number of ulcers present in the stomachs examined and the number of animals killed at each of the above-indicated times was calculated.

TABLE 3 No. of storm Number of ulcers for the various classes Variation of achs not No. of Ulcer ulcer index ulcerated Treatment Doses/kg. rats I 11 111 IV V index (percent) (percent) Controls (10% aqueous gum arabic) 20 ml 13 138 43 19 23 1 78.6

' (138) (215) (2 3-acetyl-ISB-glycyrrhetinic acid..... 436 mg 10 37 16 3 1 0 16.7 78 30 (37) (80) (30) (20) Aluminum tri-3-acetyl-18fi- 436 mg 13 72 9 0 0 0 9 -88 23 glycrrhetinate. (72) 1 Dose administered orally three times: 48 and 24 hours before the ligature of the pylorus and immediately after the operation. In brackets, the number of ulcers multiplied by the value of the various classes, in accordance with the standard of evaluation described in the methods.

TABLE 4 ACTION OF 3-ACETYLISB-GLYCYRRHETIN1C ACID AND OF ALUMINUM TRI-S-ACETYL-lSB-GLYCYRRHETINATE "O TH SEQNTAN QU EGRESSION OF IMMQBILIZATlON-INDUQED ULCERS Ulcer index at the end of the immobilization after the following numbers of days- 0 1 3 6 9 Oral doses No. of Treatment mgJkg. animals U UH U UH U UH U UH U UH Controls (gum arabic in concentration of 10% in 2ml.l100 g... 8 6.5 0 1.7 0.3 1.7 I 0.5 0.2 1 1 0 1.6

water). 3-acetyl-l8fi-glycyrrhetinic acid 436 8 6.8 0 0.6 4.2 0.2 1.2 0 1.6 0 1.7 Aluminum tri-S-acetyl-18B-glycyrrhetinate 436 0.1 3.0 0 1.6 0 1.5 0 2.3

U Ulcers not healed. U H Ulcers healed.

' Doses administered in two portions: half in the morning and half in the evening. Number of ulcers present in the stomachs divided by the number of animals killedu 5. 6 Anti-inflammatory activity stearate, talc and starch up to 1.2 g

The study of the anti-inflammatory activity was con- Powder ducted in rats by testing the oedema of the paw induced Aluminum 'tri-3-acetyl-l 8B-glycyrrhetinate 3 g both by carrageenin according to Winter et a1 (4) and Aluminum hydroxide l6 g by brewers yeast according to Van Arman et al 5 Diluents selected from sodium alginate, talc, magne- The substances under examination were administered sium stearate, polyoxyethylene stearate, starch and intraperitoneally. lactose up to 100 g The results obtained are compiled in the following Suppositories Tables. Aluminum tri-3-acetyl-l8B-glycyrrhetinate 100 INHIBITION OF OEDEMA CAUSED BY cagnAqgglguy Inhibition of Doses mg./ No. of Oedema (ml. the oedema Treatment kg. animals 13.5.) 2 (percent) Significance 3 Controls 8 0.31 $0.007 3-acetyl lSB-glycyrrhetinic acid 33 8 0.17$0.001 45 P 0.001 109 8 0.04$ 0.003 87 P 0.001

Controls 8 0.28 $0.007 Aluminum tri-3-acetyl-l8 33 8 0.17 $0.007 39 P 0.001

' 109 8 0.l4$0.0l 50 P 0.001

' Dose administered intraperitioneally twice: minutes before and 1 hour after the subplantar injection of carrageenin (0.1 ml. of a 1 percent lll- A t t y t W--. M. Mm.

Average volume of the oedema, measured 3 hours after the injection of carra geenin, the time in which the maximum volume of the oedema occurred in the controls.

Significance. deduced from Students 1" calculated with respect to the average obtained with the controls.

INHIBITION OF OEDEMA CAUSED BY BREWERS YEAST Inhibition of Doses mg./ No. of Oedema (ml. the oedema Treatment kg.-' animals ES.) 2 (percent) Significance controls s 0.31 0.003 3-acetyll SB-glycyrrhetinic acid 33 8 0.16 $0.01 48 P 0.001 109 8 0.07$0.003 77 P 0.001

Controls 8 0.29 $0.003 Aluminum tri-3-acetyl-18B-glycyrrhetinate. 33 8 0.13 0.003 55 P 0.001

' Doses administered intraggitoneallyQO ninutes bgfore the subplantar injection of brewer's yeast (0.1 ml. of a 2%, suspension).

2 Average volume of the oedema, measured 1 hour afterthe injection of brewers yeast, the time in which the maximum volume of the oedema occun'ed in the controls.

Significance deduced from Student's t calculated with respect to the average obtained with the controls.

The preparation of salts according to the invention is 40 mg illustrated in the following Examples: Tri glycerides of fatty acids up to 1,400 g Example I Ointment Preparation of aluminum tri-3-acetyl-18B- Aluminum tri-3-acetyl-lSB-glycyrrhtinate 2 g glycyrrhetinate Lidocaine hydrochloride 2 g 15.38 g of 3-acetyl-l8B-glycyrrhetinic acid dissolved Distilled water l4.8 g in 500 m1 of chloroform were added to a solution of Methyl p-hydroxybenzoate 0.2 g 2.04 g of aluminum isopropylate in ml of chloro- Diluents selected from polyethylene glycol 4,000, form. propylene glycol and cetyl alcohol up to 100 g After 1 hour, the chloroform Solut on as evaporated Suitable daily doses for humans of the compositions to ryne s, and aluminum -a y B- 50 according to the present invention are from 100 to 500 glycyrrhetinate was obtained as a white powder, meltmilligrams of the aluminum salts. ing point 286-29'0C, a 126 2(c l, CI-ICI I claim: Example II 1. A salt having anti-inflammatory and healing prop- Preparation of aluminum tri-3-acetylerties of 3-acetyl-l8B-glycyrrhetinic acid of the forglycyrrhetinate: 4.08 g of aluminum isopropylate dismula I solved in 50 m1 of methylene chloride were added to 30.76 g of3-acetyl-l8/3-glycyrrhetinic acid, suspended in 200 ml of methylene chloride. Stir at room temperature up to complete solution, then evaporate to about 50 ml and pour into 200 ml of hexane. Filter the alumi- Al(Glyc.) (OR): wherein Glyc. represents a 3-acetyl-l8B-glycyrrhetinate group; OR represents a group selected from the group consisting of hydroxy' and alkoxy; and x is 0 or a positive integer less than 3.

num tri-3acetyl-l8B-glycyrrhetinate as white amor- 2. Aluminum tri-3-acetyl-lSB-gIycyrrhetinate inacphous, light powder. cordance with claim 1.

The following are examples of pharmaceutical for- 3. An aluminum di-3-acetyl-lSB-glycyrrhetinate in mulations containing the compounds of the invention: accordance with claim 1. Tablets 4. An aluminum mono-3=acetyl-lSB-glycyrrhetinate Aluminum tri-3-acetyl-lSB-glycyrrhetinate 50 mg in accordance with claim 1. Aluminum hydroxide 400 mg Diluents selected from sodium alginate, magnesium 

2. Aluminum tri-3-acetyl-18 Beta -glycyrrhetinate in accordance with claim
 1. 3. An aluminum di-3-acetyl-18 Beta -glycyrrhetinate in accordance with claim
 1. 4. An aluminum mono-3-acetyl-18 Beta -glycyrrhetinate in accordance with claim
 1. 